This topic describes board types by function.
According to functions, boards of the SLM 1630 are classified into the following types:
An LMI board adds/drops detection signals, sends the detection signals into submarine cables for transmission, and splits backscatter optical signals from the detection signals in submarine cables for the detection of the receive end. It provides a function of near-end loopback, to locate faults between the landing station and the first RPT.
B2LMI boards apply to SLM 1630 of V100R002 or later versions, B2LMI boards have the same basic structure and functions as LMI boards.
An LMU board is used to monitor submarine equipment such as repeaters and submarine cables. It has an optical filter and can remove redundant ASE noise from receive side signal. Based on the optical time domain reflectometry (OTDR) technology, LMU boards obtain the gain change information of the repeater, to locate fault points when the submarine cable is cut. During routine maintenance, the test of line working state is provided. LMU boards provide the event analysis function for the OTDR curve reported by the line detection board, and also provide comparison and alarm reporting functions.
B2LMU boards apply to SLM 1630 of V100R002 or later versions, B2LMU boards have the same basic structure and functions as LMU boards.
An LOA board amplifies the monitoring pulse signals from LMU boards and also the Rayleigh backscatter signals from the main optical path. After the amplification, attenuation in weak signals is compensated.
When the same SLM 1630 monitors multiple pairs of submarine cables, you can select different solutions based on the actual situations of projects. Configure a monitoring module for each pair of submarine cables to achieve real-time monitoring. Only one monitoring module is available and you can use the optical switch for line selection detection based on site requirements. When one monitoring system is required to monitor multiple pairs (up to eight pairs) of submarine cables, use LSU board to monitor different submarine cable pairs at different time.
B2LAS boards apply to SLM 1630 of V100R002 or later versions. Functions provided by LOA and LSU boards are incorporated with B2LAS boards.
As a public board, an SCC board mainly provides board management and communication functions. External communication interfaces are available on the board.